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Exoskeleton robots have been widely used in many fields at present. When wearing the exoskeleton to operate, the wearer may be unconscious of the position of exoskeleton or affected by the surrounding environment, causing collision between two arms of exoskeleton or between arms and environment. The collision may result in the exoskeleton destroyed or even the wearer injured. This paper proposes a hierarchical safety control strategy for exoskeleton robots based on maximum correntropy Kalman filter and bounding box to ensure safe operation. Accurate joint angle prediction can be obtained by filtering out non-Gaussian impulsive noise using maximum correntropy criterion as evaluation criterion. Relative position relationship of the arms can be derived based on bounding box to realize hierarchical safe control. Enough experiments have been carried out, and the results validated the feasibility of the proposed method.

Population-based colorectal cancer (CRC) screening programs that use a fecal immunochemical test (FIT) are often faced with a noncompliance issue and its subsequent waiting time (WT) for those FIT positives complying with confirmatory diagnosis. We aimed to identify factors associated with both of the correlated problems in the same model.

Methods

A total of 294,469 subjects, either with positive FIT test results or having a family history, collected from 2004 to 2013 were enrolled for analysis. We applied a hurdle Poisson regression model to accommodate the hurdle of compliance and also its related WT for undergoing colonoscopy while assessing factors responsible for the mixture of the two outcomes.

Results

The effect on compliance and WT varied with contextual factors, such as geographic areas, type of screening units, and level of urbanization. The hurdle score, representing the risk score in association with noncompliance, and the WT score, reflecting the rate of taking colonoscopy, were used to classify subjects into each of three groups representing the degree of compliance and the level of health awareness.

Conclusion

Our model was not only successfully applied to evaluating factors associated with the compliance and the WT distribution, but also developed into a useful assessment model for stratifying the risk and predicting whether and when screenees comply with the procedure of receiving confirmatory diagnosis given contextual factors and individual characteristics.

In interpreting radiocarbon dating results, it is important that archaeologists distinguish uncertainties derived from random errors and those from systematic errors, because the two must be dealt with in different ways. One of the problems that archaeologists face in practice, however, is that when receiving dating results from laboratories, they are rarely able to critically assess whether differences between multiple 14C dates of materials are caused by random or systematic errors. In this study, blind tests were carried out to check four possible sources of errors in dating results: repeatability of results generated under identical field and laboratory conditions, differences in results generated from the same sample given to the same laboratory submitted at different times, interlaboratory differences of results generated from the same sample, and differences in the results generated between inner and outer rings of wood. Five charred wood samples, collected from the Namgye settlement and Hongreyonbong fortress, South Korea, were divided into 80 subsamples and submitted to five internationally recognized 14C laboratories on a blind basis twice within a 2-month interval. The results are generally in good statistical accordance and present acceptable errors at an archaeological scale. However, one laboratory showed a statistically significant variance in ages between batches for all samples and sites. Calculation of the Bayesian partial posterior predictive p value and chi-squared tests rejected the null hypothesis that the errors randomly occurred, although the source of the error is not specifically known. Our experiment suggests that it is necessary for users of 14C dating to establish an organized strategy for dating sites before submitting samples to laboratories in order to avoid possible systematic errors.

A quantitative analysis of In concentration in InGaN/GaN multiquantum wells in light-emitting diodes was carried out using high-resolution transmission electron microscopy (HRTEM) and high-angle annual dark-field scanning TEM (HAADF-STEM). The In composition in InGaN was evaluated by the precise measurement of c-lattice parameters in the HRTEM micrographs, which increase with increasing In composition. The reliability of the results was confirmed by high-resolution x-ray diffraction measurements and Rutherford backscattering spectrometry. Quantitative In compositions can, therefore, be determined using HRTEM. We tried to determine the quantitative In compositions in InGaN by analyzing the intensity profiles of the HAADF-STEM images. However, several problems were encountered, such as differences in the thickness of the region observed, carbon contamination, and ion beam damage during specimen preparation. Therefore, relative differences in composition were observed in the HAADF-STEM images.

We conducted community interviews and field surveys to determine the distribution and population of the Endangered Shortridge's capped langur Trachypithecus shortridgei, and the threats to the species, in the Dulong and Nu River valleys of north-western Yunnan Province, China. We found that c. 19 groups of T. shortridgei reside in the Dulong valley, mostly located in the southern portion of the valley. According to interview and observational records in the Gaoligong Mountains to the west of the Nu River, 12 individuals and no groups were observed. Family groups consist of one adult male, 2–3 adult females and up to five young. We estimate the population of T. shortridgei in China to be c. 250–370 individuals. Threats to the species include habitat loss and poaching. We suggest several measures to conserve T. shortridgei, such as a review of the Gaoligong National Nature Reserve management strategy, and increasing engagement, education, inclusion of local people in forest management, and the consistency of enforcement.

A centipede-like robot, which has high degrees of freedom (DOFs) and similar body segments, requires new real-time control to achieve diverse gaits. Therefore, we have studied the movement characteristics of multi-legged creatures and determined the features for a gait periodic relay. An instruction-relay control scheme, the three-bus control system and the required software were then designed. In our experiments with the designed control system, different gaits for the robot could be achieved, and the phase difference between body segments could be changed by altering the delay time. As a whole, this control system could accomplish the required control task and reasonably simplify the gait control algorithms and procedures.

Summary

Introduction: stem/progenitor cell recruitment vs. transplantation

The utilization of transplanted stem cells in regenerative medicine has been studied extensively as a potential therapy to repair or replace tissues that are lost due to trauma, congenital deformities, tumor resections, or infectious diseases [1–3]. The current cell transplantation model in regenerative medicine is founded on the principle that the application of transplanted stem cells could repopulate and regenerate damaged or diseased tissues, with restored tissue functions and homeostasis. However, cell transplantation is faced with a multitude of clinical and cell culture complications including the complexity of the multistep surgical procedures, donor-site trauma, immune rejection for allogeneic and xenogeneic cells, cell phenotypic variations due to in-vitro culture techniques, potential tumorigenesis associated with long-term cell expansion, failure of exogenous cell engraftment, and uncertainties and difficulties in the regulatory approval process [4–8]. The difficulties in the clinical application of stem cell transplantation are in strong contrast to the results of multiple experimental studies that demonstrate different levels of efficacy of cell delivery in a number of disease models such as Parkinson’s disease [9, 10], blood cancers and diseases [11, 12], and muscle and spinal disorders/injuries [13, 14].

For a number of regenerative medicine applications, the use of stem cell transplantation might not be competitive with the cost-effectiveness of current clinical treatment modalities in the dental and musculoskeletal fields, including titanium joint replacements, dental implants, and operative dental procedures [15–17]. Alternatively, the concept of endogenous stem/progenitor cell recruitment in regenerative medicine is based on the idea that native stem/progenitor cells that already reside within mature tissue can be stimulated and functionally enhanced to repopulate, repair, and/or regenerate damaged tissues [18]. Relative to stem cell transplantation, the application of endogenous stem cell recruitment in regenerative medicine is still in its infancy. The combination of the use of biological factors, release technology, biomaterials, and bioengineered scaffolds to enhance endogenous stem cell recruitment seems very promising for potential use in translational regenerative medicine. However, further scientific experimentation is warranted, since many scientific questions concerning the mechanistic details remain unresolved and it will be necessary to validate the efficacy of this approach for clinical application.

Si delta-doping in the GaN layer has been successfully demonstrated by low-pressure metalorganic chemical vapor deposition at a growth temperature of 1040 . Si delta-doping concentration increases and then decreases with an increase in delta-doping time. This indicates that delta-doping concentration is limited by the desorption process owing to much higher thermal decomposition efficiency of silane at high growth temperatures of GaN. In addition, it was observed that the use of a post-purge step in the ammonia ambient reduces Si delta-doping concentration. From capacitance-voltage measurement, a sharp carrier concentration profile with a full-width at half maximum of 4.1 nm has been achieved with a high peak concentration of 9.8 1018 cm−3.

The growth of high-quality indium (In)-rich InXGa1−XN alloys is technologically important for applications to attain highly efficient green light-emitting diodes and solar cells. However, phase separation and composition modulation in In-rich InXGa1−XN alloys are inevitable phenomena that degrade the crystal quality of In-rich InXGa1−XN layers. Composition modulations were observed in the In-rich InXGa1−XN layers with various In compositions. The In composition modulation in the InXGa1−XN alloys formed in samples with In compositions exceeding 47%. The misfit strain between the InGaN layer and the GaN buffer retarded the composition modulation, which resulted in the formation of modulated regions 100 nm above the In0.67Ga0.33N/GaN interface. The composition modulations were formed on the specific crystallographic planes of both the {0001} and {0114} planes of InGaN.

This paper presents a physical investigation and mathematical analysis on mechanical behavior of the regular jugged discontinuity. In particular, we focus on the creep property of structural plane with various slope angles under different normal stress through shear creep tests of structural plane under shear stresses. According to the test results, the shear creep property of structural plane was described and the creep velocity and long-term strength of the structural plane during shear creep were also investigated. An empirical formula is finally established to evaluate shear strength of discontinuity and a modified Burger model was proposed to represent the shear deformation property during creep.

We investigate the correlation of star formation quenching with internal galaxy properties and environment by comparing observation and theoretical models. We first classify galaxies as the most massive “central” or “satellite” in each halo in order to investigate the environmental effect. For observed central galaxies, we are unable to determine whether star formation quenching is primarily connected with halo mass or stellar mass, because these two quantities are strongly correlated. For satellite galaxies, a nearly equal dependence on halo mass and stellar mass is seen. We find that theoretical models with AGN feedback reproduce the dependence on colours and specific star formation rates for central galaxies reasonably. However, the same models seriously fail to reproduce the star formation rates of satellite galaxies by over-quenching star formation via strong strangulation: satellite over-quenching problem.

Contaminated water is one of the main sources of norovirus (NoV) gastroenteritis outbreaks globally. Waterborne NoV outbreaks are infrequently attributed to GII.4 NoV. In September 2009, a NoV outbreak affected a small school in Guangdong Province, China. Epidemiological investigations indicated that household use water, supplied by a well, was the probable source (relative risk 1·9). NoV nucleic acid material in concentrated well-water samples was detected using real-time RT–PCR. Nucleotide sequences of NoV extracted from diarrhoea and well-water specimens were identical and had the greatest sequence identity to corresponding sequences from the epidemic strain GII.4-2006b. Our report documents the first laboratory-confirmed waterborne outbreak caused by GII.4 NoV genotype in China. Our investigations indicate that well water, intended exclusively for household use but not for consumption, caused this outbreak. The results of this report serve as a reminder that private well water intended for household use should be tested for NoV.

Some recent data on minority carrier diffusion length MCDL in GaAs and certain optoelectric parameters of LEDs obtained by the authors as well as reported in the literature have been analysed to shed light on the probable configuration of certain deep levels in GaAs and related compounds. The practical implications of the results obtained are discussed from the view point of the mechanism of slow degradation of the related optoelectronic devices.

Optimization of piezoresistive microcantilevers for biosensing applications has been studied using finite element analysis. Models have been described for predicting the static behavior of cantilevers with elastic and piezoresistive layers for analyte-receptor binding. The high-sensitivity cantilevers can be used to detect changes in surface stress due to the binding and hybridization of biomolecules. Chemo-mechanical binding forces have been analyzed to understand the issues of saturation over the cantilever surface. The introduction of stress concentration regions during cantilever fabrication has also been discussed which enhances the detection sensitivity through increased surface stress.

Si delta-doping in the GaN layer has been successfully demonstrated by low-pressure metalorganic chemical vapor deposition at a growth temperature of 1040°C. Si delta-doping concentration increases and then decreases with an increase in delta-doping time. This indicates that delta-doping concentration is limited by the desorption process owing to much higher thermal decomposition efficiency of silane at high growth temperatures of GaN. In addition, it was observed that the use of a post-purge step in the ammonia ambient reduces Si delta-doping concentration. From capacitance-voltage measurement, a sharp carrier concentration profile with a full-width at half maximum of 4.1 nm has been achieved with a high peak concentration of 9.8 x 1018 cm-3

Extracellular potential is an important parameter which indicates the electrical activity of live cells. Membrane excitability in osteoblasts plays a key role in modulating the electrical activity in the presence of chemical agents. The complexity of cell signal makes interpretation of the cellular response to a chemical agent very difficult. By analyzing shifts in the signal power spectrum, it is possible to determine a frequency spectrum also known as Signature Pattern Vectors (SPV) specific to a chemical. It is also essential to characterize single cell sensitivity and response time for specific chemical agents for developing detect-to-warn biosensors. We used a 4x4 multiple Pt microelectrode array to spatially position single osteoblast cells, by using a gradient AC field. Fast Fourier Transformation (FFT) and Wavelet Transformation (WT) analyses were used to extract information pertaining to the frequency of firing from the extracellular potential.

Characterization of electrical activity of individual neurons is the fundamental step in understanding the functioning of the nervous system. Single cell electrical activity at various stages of cell development is essential to accurately determine in in-vivo conditions the position of a cell based on the procured electrical activity. Understanding memory formation and development translates to changes in the electrical activity of individual neurons. Hence, there is an enormous need to develop novel ways for isolating and positioning individual neurons over single recording sites. To this end, we used a 3x3 multiple microelectrode array system to spatially arrange neurons by applying a gradient AC field. We characterized the electric field distribution inside our test platform by using two dimensiona l finite element modeling (FEM) and determined the location of neurons over the electrode array. Dielectrophoretic AC fields were utilized to separate the neurons from the glial cells and to position the neurons over the electrodes. The neurons were obtained from 0-2-day-old rat (Sprague-Dawley) pups. The technique of using electric fields to achieve single neuron patterning has implications in neural engineering, elucidating a new and simpler method to develop and study neuronal activity as compared to conventional microelectrode array techniques.

Anisotropie short-range structure in Co-Pd alloy and Pd/Co multilayer films is determined using polarized Co K-edge extended x-ray absorption fine structure. A local modulation of Co fraction exists along the growth direction in the alloy films. Pd underlayer and Pd spacers alternated with the alloy layer influence an effective strain anisotropy. Pd/Co multilayers have an alloy-like region near nominal interfaces by diffuse interface. Pd spacers in the multilayer play a role in coherency strain rather than on broken symmetry of Co atoms. Local structural anisotropy of both strain and chemical environment contribute to the perpendicular magnetic anisotropy observed in these films.

The primary deflection due to the chemical reaction between the analyte molecules and the receptor coating, which produces surface stresses on the receptor side is analyzed. The resonance frequency of microcantilevers is very sensitive to the properties of the microcantilever surface. Biosensing experiments based on resonance frequency shift are presented, which show that the results strongly depend on the interaction of specific analyte molecules with the receptor surface.